1. Field of the Invention
This invention relates to a rotary part, in particular a spreader roller for a web-processing machine.
2. Description of the Related Art
Spreader rollers are used in web-processing machines to prevent fold formation or sagging on moving material webs by spreading the material webs. Also, spreader rollers are used to enable material webs that are arranged side by side and parallel with each other to run apart laterally. Material webs arranged side by side and parallel with each other can be produced by slitting a wide material web for example.
The spreader rollers known from the prior art usually have a curved and upright core on which several mutually independent roller segments are supported by way of roller bearings in order to simulate a curved roller in several sections.
The previously mentioned spreader rollers are complex in their construction and in their maintenance. Furthermore, on the previously mentioned spreader rollers the curvature is not adjustable.
From U.S. Pat. No. 6,524,227 there is known in addition a spreader roller on which the outer sleeve has respectively one bearing rod fitted to each longitudinal end, each rod being mounted respectively on a so-called double bearing. As there is no connection between the two double bearings, the moment input during bending of the spreader roller must be absorbed by the supports as torsional moment. Simple fixing to the supports is thus impossible.
Furthermore, in the case of spreader rollers of this type, high forces are exerted on the bearing arrangement, which can lead to high wear of the bearing.
What is needed in the art is an improved rotary part, in particular an improved spreader roller.